Crabtree VO-ELCB - retain as isolator?

[happysteve]

Assuming the property sale goes ahead as planned, I'll have the pleasure of rewiring a lovely riverside wooden chalet on the Broads. The current installation is a little - shall we say, dated?



The TT installation has an up-front Crabtree VO-ELCB:



Assuming it works as a switch, I was thinking of retaining this as an isolator, whilst I change the board, and leaving it in situ afterwards. I'm aware it has a 60A O/L (assuming it works!), which I'm relaxed about. I've seen John Ward's web page and video where he takes one of these apart - they seem well made. I will disconnect the two earth connections - I will probably use an SBS board, with compact DP RCBOs for fault and additional protection. The old coin-operated meter is going.

I'm just after opinions really on a scale of, "Yeah, that'll easily outlast any REC2S isolator," to "Oh heavens, no, it'll fall to bits as soon as you try to use it, best get rid."

Cheers

 

[Andy™]

ideally replace with an isolator, but ive left them in before. earths disconnected and it shouldnt be able to trip unless it has an internal fault

 

[Rob.]

Just disconnect the earth reference an it'll be fine as an isolator. They're built like tanks.

Might want to put a little sticker note next to it as it may catch other electricians out at a later date.

 

[Tony S]

Keep it as an isolator. It is designed to make and break fault currents, no isolator you could buy nowadays will match it

.

 

[happysteve]

Thanks Andy, Rob and Tony.

Labelling up is a good idea - perhaps covering over the text that says, "Test this protective switch often by pressing the yellow button. If it does not switch off inform your electrical contractor." A label advising that the earth leakage protective nature of the device has been disabled and that it is an isolator (with overload) only, sounds like a good plan, to avoid any unnecessary concern in the future.

Cheers

 

[Tony S]

Thanks Andy, Rob and Tony.

Labelling up is a good idea - perhaps covering over the text that says, "Test this protective switch often by pressing the yellow button. If it does not switch off inform your electrical contractor." A label advising that the earth leakage protective nature of the device has been disabled and that it is an isolator (with overload) only, sounds like a good plan, to avoid any unnecessary concern in the future.

Cheers

There is no O/L, it will just be an isolator.

 

[ProDave]

There is no O/L, it will just be an isolator.

And therefore only actually rated at 60A which may or may not be a problem to you.

 

[happysteve]

There is no O/L, it will just be an isolator.

Ah yes, thank you. I was sure it said "O/L" somewhere on it, but I see now that was the one JW took apart!

 

[Tony S]

And therefore only actually rated at 60A which may or may not be a problem to you.

I’ve taken one apart to remove the trip coil. I wouldn’t be concerned about using it on a 100A service, the contacts are well up to it.

 

[Andy™]

 it is an isolator (with overload) only, sounds like a good plan,

just like an RCD, the rating is only its rated capacity that it can safely handle, its go nothing in it to detect overload

 

[happysteve]

just like an RCD, the rating is only its rated capacity that it can safely handle, its go nothing in it to detect overload

Thanks, yes, I agree. I hadn't noticed that the version installed was different from the one John Ward took apart.

Perhaps Crabtree did two versions - one with overload, one without? I suspect I wasn't even born when they did so

 

[Andy™]

dont think ive seen any with O/L marked on them, does it say anything else on the side about it?

 

[happysteve]

dont think ive seen any with O/L marked on them, does it say anything else on the side about it?

The one in the property for sale, the only photo I have is the one I posted at the top of this thread so I don't know I'm afraid. I won't be going back for a while (even assuming the sale goes ahead).

The photo of the one with the overload on, is from the web page by John Ward, linked above the photo.

Edit (more info): there's an embedded youtube video on the link web page where he takes it apart, it's quite interesting.

Cheers

 

[Tony S]

Perhaps Crabtree did two versions - one with overload, one without? I suspect I wasn't even born when they did so

They did and I’d clean forgotten about them. They were either E/L or O/L units not both. We used 15A O/L units for control circuits. The three 4BA threaded bushings are for panel mounting. Yours is an E/L unit.